Electrical switch



April 1, 1958 A. B. BRANDLER 2,829,223

ELECTRICAL swncn Filed Sept. 5, 1956 INVENTOR. ABRAHAM B. BRANDLER f dada HIS ATTORNEY.

ELECTRICAL SWITCH Application September 5, 1956, Serial No. 608,055 3 ClliimS. (Cl- 200-170) Thisinvention relates to detachable connectors and relates more particularly toan improved electrical switch employing a blade received ina pair of contact jaws.

Animportant object of the present invention is to pro vide an electrical switch for increasing the pressure between the blade and the contact jaws and securing thereby a decrease of contact resistance and a reduction of voltage drop and energy losses .due to infirm contact surfaces. 7

Another object of the invention is to provide a novel electrical connector for high current conduction with simple and effective means for obtaining a high contact pressure while permitting easy manipulation of the switch.

Yet another object of the invention is the provision of improved means for increasing pressure between a switch blade and contact jaws which can be applied to standard switches without changing their basic construction in any way whatsoever.

To this end the invention comprises a 'novel spring plate which can be applied, usually in pairs, to opposite sides of the pivoted blade of the switch and which is equipped with one or more rolling elements which can be rollers or balls which engage the outer faces of the contact jaws. By virtue of the inherent resiliency of the plate the rollers exert a considerable pressure against the contact jaws which in turn are urged against the blade with a far greater degree of pressure than is the case if the jaws alone exerted this pressure.

Various adjustable means have been employed for increasing the pressure between contact members and switch blades but these structures require periodic adjustment. unique in that it maintains its pressure undiminished during the entire useful life of the switch. Switch jaws have a tendency to get out of line, especially if the corners thereof are struck by the blade during closing of the switch. Also in some instances if the switch has temporarily carried too much current the jaws tend to soften, especially of they tend to heat up during use. The heat aparently has a tendency to anneal the copper. The situation sometimes becomes so bad that workers will use a C clamp for holding the jaws against the blade which, of course, is not a recommended practice.

Basically the improvement of the present invention is a clamping element carried by the blade which does not require hard manipulation, as does the C clamp, and it is provided with some anti-friction element such as rollers or balls which permits easy closing and opening of the switch.

In the drawing:

Fig. 1 is a broken perspective view of a switch embodying the present invention.

Fig. 2 is a perspective view of the arched plate.

The improvement of the present invention is 1 United States PatentO Fig. 3 is a plan view thereof and showing a modification in its construction.

A single throw switch having a single blade 10 is shown in Fig. 1, the blade being pivotally mounted at one 2,829,223 7 Patented Apr. 1, 1958 end thereof on a post 11 suitably secured to a base 12. A handle 13 at the opposite end of the blade serves to permit manual manipulation of the blade to bring it into engagement with apair of resilient jaws 14 which may be formed integrally with a base portion 15 secured to base 12. The jaws usually have a vertical saw cut to increase their resiliency.

The improvement constituting the present invention includes one or a pair of resilient arched plates 16 supporting a shaft 20 on which one or more rollers 21 are freely carried. A small switch might have only one roller-carried by each plate whereas a larger may have two or more. The spring plate may be stamped from sheet metal and is of generally rectangular shape.

At the four corners there are provided downwardly extending legs 22 having fiat attaching ears 23 with holes 24. On the upper face of the plate adjacent each leg there is a substantially V-shaped cut-outsection shown at 25 and a central projection 26 located between the notches 25 is bent downwardly at its outer end forming an apertured bearing 30 for a shaft 20 which supports the roller.

The plate is provided with a rectangular opening 33 for each roller and of such size as to permit free rotation thereof. Since the shaft is usually formed of bendable wire supports for the shaft are formed intermediate its bearing ends comprising a central, curved struck-out semicylindrical portion 34 located between the rollers and two terminal struck-out portions 35. Thus as the rollers and their shaft tend to move outwardly due to engagement under pressure with the contact jaws these struck-out portions which are engaged by the shaft form bearing surfaces limiting such outward movement.

One of the arched plates is mounted on each side of the blade 10 as by means of rivets passing through holes 24 and the broad central section thereof lies in spaced relation to the blade. As the blade is moved to closed position the rollers engage the contact jaws on their outer faces. The relationship of the parts in such that when this occurs the rollers and the supporting parts of the plates are cammed outwardly while exerting considerable pressure on the jaws. The bending moment takes place largely in the relatively narrow connecting areas shown at 37 between the outer corners of slots 33 and the inner ends of V-shaped notches 25. These notches should not extend inwardly. so far as to Weaken these bending areas but the areas should not be so narrow as to deprive the shaft supporting elements of a desired measure of resiliency.

In Fig. 3 the shaft 20 is centrally split as shown which arrangement is sometimes preferable since both antifriction elements can independently find their own inner I levels.

While there have been described herein what are at present considered preferred embodiments of the invention, it will be obvious to those skilled in the art that many modifications and changes may be made therein without departing from the essence of the invention. It is therefore to be understood that the exemplary embodiments are illustrative and not restrictive of the invention, the scope of which is defined in the appended claims, and that all modifications that come within the meaning and range of equivalency of the claims are intended to be included therein.

What I claim is:

l. The combination with an electrical switch having a pair of spaced contact jaws mounted on a base and a pivoted blade also mounted on the base and movable be tween the jaws, of resilient means engaging the outer face of at least one jaw for yieldingly urging it into firm contact with the blade, said means comprising an arched spring plate carried, on the blade and a roller freely rotatable on the plate, said plate having an aperture for the roller and offset legs to mount the central section of the plate in spaced relation to the blade, springextension portions at each end of the plate whose terminalsarc dis posed at right angles thereto forming bearings, and a shaft carrying the roller, mounted in saidbearings, the

plate having notches adjacent the outer endsof the roller opening forming narrow bending areas to allow the projections and the roller to be yieldingly displaced outward 1y as the rollers contact the jaws.

2. The combination with an electrical connector having a pairof spaced contact jawsmounted on a base and a pivoted blade alsornounted on the base and movable between the jaws, of resilient means engaging the outer faces of the jaws for yieldingly urging them into firm contact with the blade, said means comprising an arched spring plate carried on each side of the blade and plural rollers freely rotatable on the plate, said plate having apertures for therollers and offset legs to mount the central section of the plate in spaced relation to the blade, bendable extension portions at each end of the plate whose terminals are bent at right angles thereto forming bearings, and a shaft carrying the rollers, mounted in said bearings, the plate having notches adjacent the outer ends of the roller openings forming narrow bending areas to 4 allow the projections and the rollers to be yieldingly displaced outwardly as the rollers contact the jaws.

3. An electrical switch comprising a pair of spaced contact jaws mounted on a base and a pivoted blade also mounted on the base and movable between the jaws when the switch is closed, and resilient means engaging the outer faces of the jaws for yieldingly urging them into firm contact with the blade, said means comprising an arched spring plate carried on eachside of the blade and extending around the jaws, plural rollers freely rotatable on the plate, said plate having apertures for the rollers and offset legs to mount the central section of the plate in spaced relation to the blade, bendable extension portions at each end of the plate whose terminals are disposed at right angles thereto forming bearings, and a shaft carrying the rollers mounted in said bearings, additional bearing surfaces for the shaft formed in the inner face of the plate, the plate having notches adjacent the outer ends of the roller openings forming narrow bending areas to allow the projections and the rollers to be yieldingly displaced outwardly as the rollers contact the jaws.

References Cited in the tile of this patent UNITED STATES PATENTS 1,891,935 Lapsley Dec. 27, 1932 

